This application i s based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-084335, filed Mar. 26, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to an exchange jig for a heavy object such as an X-ray tube incorporated in the gantry of a medical image sensing apparatus such as an X-ray computed tomography apparatus (X-ray CT) or magnetic resonance imaging apparatus (MRI), a bed device, and an X-ray computed tomography.
FIG. 1A is a sectional view showing the gantry of a conventional X-ray computed tomography apparatus. A gantry frame 41 supports a rotating ring 42. The rotating ring 42 can rotate. An X-ray tube 44, high-voltage generator 45, X-ray detector 46, and the like are mounted on the rotating ring 42.
The X-ray tube 44 is as heavy as 25 kg for a light tube and 65 kg for a heavy tube. The high-voltage generator 45 and X-ray detector 46 are also heavy. Exchange work of dismounting an old X-ray tube from the rotating ring 42 and mounting a new one is very hard work. To assist this exchange work, the gantries of most conventional X-ray computed tomography apparatuses incorporate exchange jigs (crane mechanisms) for assisting work of exchanging an old X-ray tube or the like with a new one.
A column 50 of an exchange jig 48 is attached almost perpendicularly to, e.g., a holder 49 of the gantry frame 41. The column 50 is coupled to an almost horizontal arm 51. A reel 53 hangs from the distal end of the arm 51. A hook 52b is connected to the end of a wire 55 of the reel 53.
In exchange work, an old X-ray tube 44 is tied with a rope 54, which is hooked on the hook 52b. The X-ray tube 44 is dismounted from the rotating ring 42, and pulled up by the reel 53. As shown in FIG. 1B, the column 50 is axially rotated to remove the X-ray tube 44 outside the gantry. The X-ray tube 44 is put down on the floor by the reel 53. The X-ray tube 44 is released from the rope 54, and loaded on a truck. A new X-ray tube 44 is mounted in a reverse order to the dismounting order.
FIG. 2A shows another exchange jig 61. A slide rail 61a is almost horizontally attached to a gantry frame 41. A slide frame 61b can slide along the slide rail 61a. A hook 63 hangs from the reel 65 of the distal end of the slide frame 61b. 
In exchanging an X-ray tube 44, a rope 64 which ties an old X-ray tube 44 is hooked on the hook 63. The slide frame 61b is slid and the reel 65 is lowered, to remove the X-ray tube 44 outside the gantry frame 41. Then, the X-ray tube 44 is loaded on a transport truck. A new X-ray tube 44 is mounted in a reverse order to the dismounting order.
As described above, the gantries of most conventional X-ray computed tomography apparatuses incorporate exchange jigs. This is one of factors that enlarge the gantry.
Since the rotation radius of the arm 51 and the slide length of the exchange jig 61 are short, the X-ray tube cannot be directly loaded from the exchange jig on the truck. The X-ray tube must be temporarily put down on the floor, and then loaded from the floor on the truck. This decreases the workability, and may inhibit exchange work using the exchange jig in a small CT room.
It is an object of the present invention to simplify exchange work of a heavy object such as an X-ray tube.
The present invention provides an exchange jig for assisting work of exchanging a heavy object such as an X-ray tube. This exchange jig has a detachable unit, which enables attaching/detaching the exchange jig to/from the top plate of a bed. In exchange work, the exchange jig is attached to the top plate of the bed. The elevating function and top plate slide function of the bed realize a forklift function together with the support function of the arm unit of the exchange jig. If exchange work is not performed, the exchange jig can be detached from the top plate of the bed. The arm unit is attached to the detachable unit through a rotating unit. The rotating unit freely rotates about an almost vertical axis. This rotation facilitates work of transferring the heavy object between the arm unit and a gantry, and work of transferring the heavy object between the arm unit and a truck.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.